iPhone activation question

[dukebound85]

Will an expired att sim still activate an iphone? I ask as once I am out of my contract, will my device be rendered useless if I update the os and happen to change carriers?

I know about hacktivating but would rather be able to enjoy updates as they comeout

 

[Applejuiced]

Yes any AT&T sim will activate it, even old inactive AT&T sims.
But activating doesn't mean unlocking so it won't work with any other carriers sim cards.